1. Field of the Invention
The present invention relates to a prebent ceramic suspension and more particularly to an integrated suspension-slider-magnetic head for a multiple disk magnetic disk drive.
2. Description of the Related Art
A magnetic disk drive includes a magnetic disk and a magnetic head. When the disk is rotated the magnetic head reads and writes magnetic signals on circular tracks on the disk. The magnetic head is typically mounted to a slider which is, in turn, mounted to a suspension (load beam), the suspension biasing the slider toward the disk which is referred to in the art as "preloading." The suspension is mounted to an actuator arm of an actuator, the actuator being a voice coil or a longitudinal solenoid depending upon whether the circular tracks of the disk are accessed radially or longitudinally. Both types of actuators employ an electromagnet. If the actuator is a voice coil the actuator arm carries a coil which, upon selective energization, cooperates with the electromagnet to move the slider radially across the magnetic disk to desired tracks.
In a quiescent state of the disk drive the suspension preloads the slider on the magnetic disk. When the magnetic disk is rotated the disk swirls air between the disk and the slider producing a hydrodynamic layer which separates the slider from the surface of the disk. When this occurs the slider and the magnetic head literally "fly" above or below the surface of the disk. The cushion of air is referred to as an "air bearing" and the surface of the slider riding on the air bearing is referred to as an "air bearing surface" (ABS).
In a high capacity disk drive multiple double sided disks are vertically stacked and are read and written by multiple magnetic heads, the multiple magnetic heads being mounted to multiple sliders, the multiple sliders being mounted to multiple suspensions and the multiple suspensions being mounted to multiple actuator arms. A pair of suspensions are mounted to a single actuator arm and the suspensions are positioned between adjacent disks in the stack. With this arrangement one magnetic head reads and writes on the bottom of one disk and the other magnetic head reads and writes on the top of the other disk.
A typical prior art suspension is made from metal which is bent in a plastic state to bias the slider toward the disk. The slider, which carries the magnetic head, is bonded to one end of the suspension and the other end of the suspension is affixed to one end of the actuator arm. The attachment of the slider to the suspension and the attachment of the suspension to the actuator arm is a labor intensified job. The sliders are referred to as "chiplets" because they are small and are fabricated by thin film technology. Each chiplet has to be accurately bonded to the suspension within a close tolerance. In order to simplify fabrication of these disk drive components it has been proposed to construct an integrated magnetic head-slider-suspension by thin film technology. The slider and the suspension are constructed of a ceramic, typically alumina. A copending patent application Ser. No. 08/366,282, filed Dec. 29, 1994, commonly assigned to IBM goes one step further and proposes constructing an integrated magnetic head-slider-suspension-actuator arm. The advantage of integrating these components is that they are connected with precision. With thin film batch construction literally hundreds of integrated units can be made on a single wafer.
In thin film construction multiple thin film layers are formed by photopatterning, plating and sputtering on a wafer. When the construction is completed the integrated units are released from the wafer, each integrated unit being an integrated magnetic head-slider-suspension. All of these units are flat. The integrated magnetic head-slider-suspension is then attached to an actuator arm. In order to bias the slider toward a disk one end of the suspension is attached to a slanted surface on the actuator arm. With this arrangement an actuator arm is employed with each suspension which results in two actuator arms being employed between adjacent disks. This decreases disk stacking density as compared to the prior art single actuator arm which carries two prebent metallic suspensions. There is a strong felt need to capitalize on the benefits of integrated magnetic head-slider-suspensions without losing disk stacking density in a multiple disk drive.